Switch or junction box



y 1934. E. M. ROSENFIELD SWITCH 0R JUNCTION BOX Filed May 4, 1931 5 0 n 1. 4 i 2W M 0 6 2 2 6 N d m V E l m mm W w. WA w rlllllw zww lllllm I. 1W m 6. I. R 5% W 2 w B VII/A FY30 ingthe invention.

Patented July 17, 1934 r remiss *ISWIT'CH oe common -B'OX I 'Edvav -M-Bqm fl N w i KPN-YQ s n to Standard Electric Equipment Corporation -a v corporation'otfbelaware. V V

V rnpplicationrMay 4, 193-1, sel'i'al N0. 534,7 13

' .5 Claims. ((31. 2471-9215) p ."l'hls invention frelates to sheet "metal fe'lectri'c switch orfjunctiojn boxes, "such as used in electric wiring -instime.trons and more articularly, is directed *to improve'dimeans for removing knock- 'olitsflprovidedln sai'd boxes; l Among/the 'obj'ectsfbf the invention ifsto gen- 'erally improve the construction or knock-outs of, electric boxes by providing dislodging means whereby said ammonia-may "be readily removed from their fseatedij'position from the exterior side er thebo'x thereby eliminating an inter- Ierence with the cable clamping or wiring within the boxes, saidfkncckoutsf construction "being formed of ffewfandfsimpl'e ,partswhich shall be cheap "to fabricate, andfpractical 'an'd'eflicient to a high degree 'i'n'use.

I TOtherobje'cts of f thls inventionwill in part be obviousandinjparthereinaiter pointed out.

The invl ntion accordingly consists in the fea- 320 tur'es 10f co tructi'on, combinations of elements and arrangement .of parts "which will be "exempiified in the constructions"hereinafter "described and of which 'thescop'e of application will be indicated in the following claims.

525 "Irftheaccompfanyingidrawing,'in'which is shown various pdssible illustrative embodimentsnj this invention. 1 y y "1 Fig; ,1 is alperspe'ctivejview of an electric junction or switchfbox hfaving knock-outs embody- Fig. 2a is a. fragmentary cross-sectional View.

simna'm mg; '2 fshcwing the se material or "d ib y l'a partially severed p'eriphi r im-J; A i jfFigfe i aifragmeritary:perspectiveviewshowing 'tnemefthcd dffiislo'd'gingiasmock-out" by prying cut."'

ao 4 ,israzfragmentarylpferspective view of a switch boxlialvlng'a "knock-but provided with a V-form of prying means embodying the invention.

Fig. 5 is a cross-sectional view taken on lines 5-5 in Fig. 4.

1150 lines 7-7 in Fig. 6.

Referring in detail to the drawing, denotes an electric switch or junction box of the conventional construction formed of steel stamped parts having end walls 21 usually formed integral "155. with the bottom side of the box 22, and detachable side "walls 23, fth'e latter being retained 'in position "through the f interlocking connection 24 and theserew fastening -25 "in the "wellunderstood 'manner and'as'shownin Fig. 1.

The'box 20 has"linock-cutsf zewm har pr vided in the "end walls 21, the'bottorn' side 22' of the box, "andin theside walls "23 v These *knocke jouts'fifzc maybe or any desired-shape; preferably beingcircular antl'of a diameter to correspond Ftb the diameterof standardsizes of conduits 01",(581- bles (not-shown). Said knock out'sif26 may be formed in the well understoodmanner'by a punch 'and'die the metalbeingseveredalong singleconj tinubir's lines 26a leaving ans ered "portions 261) "for retaining thejknock-o1its 'in positionas -removable closures *for'the openings 26c ihthe' wens -2'1,'22anu23. f

"fiin'ce thesefknock-outs 26 are in manycases positioned in close proximity toelectric cable clampingfmeans inside the box {20 (not shown), it is often convenient tobe "able to remove the lgnok outs from the exterior "side "oifthe box "without the necessityof reaching into "the-box to dislodge same from their effective closing"p'osi= tiojn To thisend, the invention herein described and "claimed is directed in providingn each knoc-k out 26 suitable means "for *engagih'gwi'th a-suitable rying "tool such a screw driver s or hammer. Ihth'eformshown in Figs; 1, 2am 3, this pry-engaging me'ans comprisesfa centralflyflocatec punched slot "26H which extends'trans- "versel y through the mid-portion dffi'the knock cuts '26. Said smtmay preferably Jae-positioned wholly within the may dft h'ef knock-out iii-'- wardly from the severedlineffiifi'hf Materialsfo'r '90 pun'chi'ngs "266 of the knock-outs 26 within the slots 2212 "may "be left in position to form closures tor 'said slots, asishow'n inFigs. '1 and "2 so as to eliminate through perforations in the walls and bdtto'm side "of "the "box, since 'such "perforations a're considered "objectionable because they provide communication between the interior and exterior of the box which may form a possible fire hazard in case of a defect in the Wiring in- U stallation or arcing of switch parts within the T00 box.

One of the preferred constructions of knockou 26 and slot material 26c with relation to the box wall is clearly shown in Fig. 2, the knock-out being pressed in an outwardly dirot rection a small distance, and the slot material 266 being pressed in an inwardly direction a small distance with respect to the knock-out 26.

The utility of the invention is now apparent. 1T0

In forming the knock-outs 26, the slots 26d are formed as shown in Fig. 2. In order to remove the knock-outs 26, a blade of screw driver S or similar tool is used. A slight blow given on the exterior side of the slot material 26c with screw driver blade dislodges the slot material 26c permitting the blade to enter the slot 20d. By swinging the screw driver S the knock-out 26 is pried outwardly from the opening 260 as is clearly shown in Fig. 3. When the knock-outs" 26 are forced out sufficiently from the plane of the wall 21, the unsevered portion 26b which connects and retains the knock-outs to the wall breaks off leaving the opening 260 free for receiving an end of an electric cable, conduit, or the like in the well understood manner.

Instead of entirely severing the slot material 26c from the knock-out 26, one or more por-, tions may be only partially cut through as at 26] as shown in Fig. 2a which will allow the slot material 26eto be dislodged from the opening 26c,'yet remain attached to the knock-out.

In Figsai and 5, a modified form of the invention is shown. Here the pry-engaging means comprises of a V-shaped slot 36d in which the slot material 36a is removed by abutting a blade of the screw driver S on one of the legs of the V and giving the screw driver a slight blow so as to dislodge said slot material thus leaving the whole or one leg of V-shaped slot free for en- .tering the blade to permit the outwardly prying operation. By providing a V-shaped slot 36d in place of a straightslot 26d, shown in Figs. 1 to 3, the prying movement with the screw drivers can be selectivelyv accomplished in either one of two directions, the prying being carried out in a direction which is most convenient. Sometimes the box 20 is so installed that no space is available to swing the screw driver in one direction for prying. -In such cases, the screw driver can be entered into the leg of the V for prying in the other direction thus giving the workman greater latitude for prying move- .ment.

.of providing means for prying in a plurality of directions, other shapes may be used as for example, L, T, triangle, star, etc.

The slot materials 366 and 46e shown in Figs. 4 and 6, may be formed with one or more portions only partially cut through as explained for the knock-out shown in Fig. 2a to retain them to the knock-out, yet permit said slot materials 36c and 46e to be dislodged from their corresponding openings. If desired, the slot materials 366 and 466 may be severed to sectionalize them so that only suflicient material is dislodged to permit the insertion of the blade of the prying tool as is apparent.

It will thus be seen that there is provided means whereby the several objects of this invention are achieved and which are well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and'desirev to secure by Letters Patent:

1. An electric switch box formed of sheet metal having a severed disc-shaped pry-out adapted to be removed for providing an opening, said pryout having a pair of'intersecting narrow slots ina mid-portion thereof. for selectively entering means to pry the pry-out free from said opening, the edges of each of said slots being constructed and arranged to serve as a bearingalong substantially the entire length engaging said prying means.

2. An electric wall box having a severed wall portion retained in position to provide a knockout, said portion having a pair of intersecting elongated slots adapted to receive a tool for dislodging said knock-out from its retaining position byprying movement exerted in either one of two planes, each prying movement corresponding selectively to one of said slots.

3. In an electric protective means a casing having a pry-out in a Wall thereof, said pry-out being provided with a pair of elongated intersecting slots extending through the thickness'thereof for the reception of a prying tool whereby prying movement corresponding selectively to one of said slots, said slots lying within the boundary of said pry-out.

4. In an electric protective means, a casing having a pry-out in a wall thereof, said pry-out being provided with a V-shaped opening extending through the thickness thereof for thereception of a prying tool whereby prying movement in one of a plurality of planes may be exerted to pry loose said pry-out from said wall, said opening lying within the boundary of said pryout.

'5. In an. electric protective means, a casing having a pry-out in a wall thereof, said pry-out being provided with an X-shaped opening for the reception of a prying tool in various angular positions whereby said pry-out may be pried loose from said wall, said opening lying within the boundary of said pry-out.

EDWARD M. ROSENFIELD. 

